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Decompiles Overlay_DoRelocation (#149)

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* decompile Overlay_DoRelocation

* add non-matching comments
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krimtonz 2020-05-20 07:53:42 -05:00 committed by GitHub
parent 43dfaa7518
commit 9a478a96ec
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 129 additions and 3 deletions
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126
src/code/relocation.c
View file

@ -1,3 +1,129 @@
#include <global.h>
#ifdef NON_MATCHING
void Overlay_DoRelocation(void* allocatedVRamAddress, OverlayRelocationSection* overlayInfo, void* vRamAddress) {
// mostly regalloc, more specific issues described below.
u32 sections[4];
u32 unrelocatedAddress;
u32 dbg;
u32 relocatedValue;
u32 relocOffset;
u32 relocatedAddress;
u32 i;
u32* relocDataP;
u32* luiRefs[32];
u32 luiVals[32];
u32 relocData;
u32 reloc;
u32 vaddr;
u32* luiInstRef;
u32 addrToLoad;
u32 luiInst;
u32* regValP;
u32 isLoNeg;
relocOffset = 0;
relocatedValue = 0;
unrelocatedAddress = 0;
relocatedAddress = 0;
if (gOverlayLogSeverity >= 3) {
osSyncPrintf("DoRelocation(%08x, %08x, %08x)\n", allocatedVRamAddress, overlayInfo, vRamAddress);
osSyncPrintf("text=%08x, data=%08x, rodata=%08x, bss=%08x\n", overlayInfo->textSize, overlayInfo->dataSize,
overlayInfo->rodataSize, overlayInfo->bssSize);
}
sections[0] = 0;
sections[1] = (u32)allocatedVRamAddress;
sections[2] = sections[1] + overlayInfo->textSize;
sections[3] = sections[2] + overlayInfo->dataSize;
for (i = 0; i < overlayInfo->nRelocations; i++) {
reloc = overlayInfo->relocations[i];
relocDataP = (u32*)(sections[reloc >> 0x1E] + (reloc & 0xFFFFFF));
relocData = *relocDataP;
switch (reloc & 0x3F000000) {
case 0x2000000:
/* R_MIPS_32
* handles 32-bit address relocation. Used in things such as
* jump tables.
*/
if ((*relocDataP & 0xF000000) == 0) {
relocOffset = *relocDataP - (u32)vRamAddress;
relocatedAddress = relocOffset + (u32)allocatedVRamAddress;
relocatedValue = relocatedAddress;
unrelocatedAddress = relocData;
*relocDataP = relocatedAddress;
}
break;
case 0x4000000:
/* R_MIPS_26
* handles 26-bit address relocation, used for jumps and jals
*/
unrelocatedAddress = ((*relocDataP & 0x3FFFFFF) << 2) | 0x80000000;
relocOffset = unrelocatedAddress - (u32)vRamAddress;
relocatedValue =
(*relocDataP & 0xFC000000) | ((((u32)allocatedVRamAddress + relocOffset) & 0xFFFFFFF) >> 2);
relocatedAddress = ((relocatedValue & 0x3FFFFFF) << 4) | 0x80000000;
*relocDataP = relocatedValue;
break;
case 0x5000000:
/* R_MIPS_HI16
* Handles relocation for a lui instruciton, we just store the reference to
* the instruction, and will update it in the R_MIPS_LO16 section.
*/
luiRefs[(*relocDataP >> 0x10) & 0x1F] = relocDataP;
luiVals[(*relocDataP >> 0x10) & 0x1F] = *relocDataP;
break;
case 0x6000000:
/* R_MIPS_LO16
* here we will update the LUI instruction to reflect the relocated address.
* The full address is calculated from the LUI and lo parts, and then updated.
* if the lo part is negative, we make sure to add 1 to the lui.
*/
regValP = &luiVals[((*relocDataP >> 0x15) & 0x1F)];
vaddr = (*regValP << 0x10) + (s16)*relocDataP;
luiInstRef = luiRefs[((*relocDataP >> 0x15) & 0x1F)];
if ((vaddr & 0xF000000) == 0) {
relocOffset = vaddr - (u32)vRamAddress;
addrToLoad = relocOffset + (u32)allocatedVRamAddress;
isLoNeg = ((addrToLoad & 0x8000) ? 1 : 0);
luiInst = *luiInstRef;
*luiInstRef = (luiInst & 0xFFFF0000) | (((addrToLoad >> 0x10) & 0xFFFF) + isLoNeg);
unrelocatedAddress = (luiInst << 0x10) + (((s16)relocData) & (0xFFFFFFFFFFFFFFFFu));
relocatedValue = (*relocDataP & 0xFFFF0000) | (addrToLoad & 0xFFFF);
// The conversion of relocatedAddress to s16 is wrapped around the OR operation of
// relocated value
relocatedAddress = (*luiInstRef << 0x10) + (s16)relocatedValue;
*relocDataP = relocatedValue;
}
break;
}
if (1) {
dbg = 0x10;
switch (reloc & 0x3F000000) {
case 0x2000000:
dbg = 0x16;
case 0x4000000:
dbg += 0xA;
case 0x6000000:
if (gOverlayLogSeverity >= 3) {
osSyncPrintf("%02d %08x %08x %08x ", dbg, relocDataP, relocatedValue, relocatedAddress);
osSyncPrintf(" %08x %08x %08x %08x\n",
((u32)relocDataP + (u32)vRamAddress) - (u32)allocatedVRamAddress, relocData,
unrelocatedAddress, relocOffset);
}
break;
default:
continue;
}
}
// The loop seems to be incremented, then checked, but the conditional is a likely vs non, so it could
// potentially resolve itself.
}
}
#else
#pragma GLOBAL_ASM("asm/non_matchings/code/relocation/Overlay_DoRelocation.s")
#endif

6
src/overlays/actors/ovl_En_Dha/z_en_dha.c
View file

@ -208,7 +208,7 @@ void func_809ECA50(EnDha* this, GlobalContext* globalCtx) {
}
} else {
unkVar = ~0x80;
if (player->stateFlags2 & 0x80) {
if (player->stateFlags2 & 0x80) {
if (&this->actor == player->actor.attachedA) {
player->stateFlags2 &= unkVar;
player->actor.attachedA = NULL;
@ -230,7 +230,7 @@ void func_809ECF60(EnDha* this) {
void func_809ECF8C(EnDha* this, GlobalContext* globalCtx) {
Player* player = PLAYER;
if (player->stateFlags2 & 0x80) {
if (player->stateFlags2 & 0x80) {
if (&this->actor == player->actor.attachedA) {
player->stateFlags2 &= ~0x80;
player->actor.attachedA = NULL;
@ -267,7 +267,7 @@ void EnDha_Die(EnDha* this, GlobalContext* globalCtx) {
Vec3f vector;
Player* player = PLAYER;
if (player->stateFlags2 & 0x80) {
if (player->stateFlags2 & 0x80) {
if (&this->actor == player->actor.attachedA) {
player->stateFlags2 &= ~0x80;
player->actor.attachedA = NULL;